The present invention relates to a medium or small capacity air compressor which is used as a power air source or the like for factories, and more particularly to a heat exchanger provided in those air compressors.
A screw-type compressor and a compact turbo compressor are known as a medium or small capacity air compressor whose discharge pressure is approximately 0.7 MPa in gauge pressure and whose output power is in a class from less than 100 kW to several hundreds kW, and are used as a power air source for factories. An example of such an air compressor is disclosed in JP-A-8-105386 or JP-A-2000-120585. In these specifications, a laminated type of heat exchanger or a fin tube type of heat exchanger is used for cooling compressed air generated by the medium or small capacity turbo compressor.
In JP-A-8-105386, a gas cooler for cooling the compressed gas is inserted with a predetermined gap into a cooler shell through which the compressed gas flows while a seal part is formed on an outer circumferential part of the gas cooler for sealing the gap to divide the inside of the cooler shell into a high temperature side and a low temperature side, so that the seal part of the gas cooler has rigidity and sealability. The seal part projects from the outer circumferential part of the gas cooler, and is elastically contacted with an inner wall of the cooler shell. Further, JP-A-2000-120585 discloses a pressure container provided with a pair of rails having a recess part at one end thereof, in which a nest accommodated in the pressure container is provided with a roller to be fitted into the recess part after traveling on the rail, so that reliability and maintenance efficiency of the seal are improved.
The sealing ability is improved by way of each sealing method described in the above prior art, however, it becomes complicated to process the seal part because of its complicated structure. In addition, the assembling is troublesome because the elastic seal becomes resistant when the nest is inserted into a casing. Further, it is also difficult to completely prevent leakage.